Partner spotlight: Master Inbox
Master Inbox is a unified inbox that combines social and email conversations for sales teams. See how it connects to OutboundSync in beta.
Jason Ma
Masterinbox → HighLevel
Masterinbox + HighLevel integration
Agencies running replies through Master Inbox can show clients every conversation in HighLevel. OutboundSync writes each event as a Note on the client's Contact.
BetaOne-way syncEmail and social
Masterinbox + HighLevel at a glance
Master Inbox connects to HighLevel through OutboundSync. Outgoing and incoming messages from the email and social inboxes connected to Master Inbox, plus label changes and prospect list changes, are written as plain-text Notes on the matching HighLevel Contact in one authorized sub-account.
| Status | Beta (HighLevel is a one-way beta CRM) |
|---|---|
| Channels | Email and social |
| Direction | One-way, Masterinbox → HighLevel |
| HighLevel records | Contacts in one sub-account (Location) |
| Block lists | Not available for this pairing |
| Masterinbox plan | Needs webhook access |
| Setup | Guided: Location OAuth in-app, then source setup with the OutboundSync team |
Agencies use Master Inbox to manage replies for many clients across many senders. OutboundSync gives each client a view of that work in their own HighLevel sub-account: every message and label change lands as a Note on the Contact the conversation belongs to.
Clients see the qualification your team applied along with the messages. When a label moves to interested, the Note says so, and the client's team can take it from there in HighLevel.
What syncs from Masterinbox to HighLevel
Every event below arrives in near-real time and lands on the matched HighLevel record. Pick the ones you want per source.
| Event | Channel | Where it lands in HighLevel |
|---|---|---|
| Message sent— Outgoing messages from connected accounts, logged as email sends | Plain-text Note on the Contact | |
| Email received— Incoming messages on connected email accounts | Plain-text Note on the Contact | |
| Social message received— Incoming messages on connected social accounts | Social | Plain-text Note on the Contact |
| Label changed | Plain-text Note on the Contact | |
| Prospect list changed | Plain-text Note on the Contact |
Event names come from the Masterinbox webhooks OutboundSync receives. HighLevel is a one-way beta, so exact event coverage is confirmed during onboarding. See the Masterinbox event reference.
What teams do with Masterinbox + HighLevel
Show managed replies
Clients see every Master Inbox conversation their agency handled on their own Contacts.
Pass qualified leads
Interested labels in Master Inbox show up on the Contact for the client to act on.
One sub-account per client
Each connection writes only to the Location you authorized.
Ways to connect Masterinbox and HighLevel
The options teams weigh before they commit a production sync.
| Option | What it does | Trade-off |
|---|---|---|
| Zapier, Make, or n8nCompare integration platforms | Catch Masterinbox webhooks and write each event to HighLevel with a workflow you build. | Every event type, retry, and field change is a workflow you maintain, billed per task or step. |
| Custom buildBuild vs buy | Write your own service against the Masterinbox and HighLevel APIs. | You own matching, deduplication, API limits, and every upstream schema change. |
| OutboundSync | Pre-built email and social activity sync into HighLevel Contacts. | One-way beta with guided onboarding. Lighter configuration than HubSpot or Salesforce today. |
How to set up Masterinbox + HighLevel
Step 1: Connect HighLevel
Authorize the HighLevel sub-account (Location) from CRM Settings in OutboundSync with the same email you use to log in.
Step 2: Connect Masterinbox
The OutboundSync team creates your Masterinbox source with you and points Masterinbox's webhooks at it.
Step 3: Create the HighLevel source
Select Masterinbox when you create the HighLevel source, and confirm how contacts are matched.
Step 4: Send a test event
Trigger one Masterinbox event and confirm it on a real HighLevel Contact.
Step 5: Go live
Launch with the OutboundSync team watching the first production events in HighLevel.
Plan requirements
Masterinbox plan
Needs webhook access
OutboundSync receives Masterinbox activity through webhooks. Confirm your Masterinbox plan includes webhook access, or ask us to check during setup.
HighLevel
HighLevel is a one-way beta. There is no HighLevel plan gate on our side; onboarding runs with the OutboundSync team.
Related integrations and guides
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TapcheckMasterinbox + HighLevel FAQ
What Masterinbox activity does OutboundSync sync to HighLevel?
Message sent, email received, social message received, label changed, and prospect list changed.Which HighLevel records does it write to?
OutboundSync matches or creates HighLevel Contacts. Masterinbox events land as plain-text Note on the Contact. See the HighLevel beta guide for details.Do Master Inbox messages show up as HighLevel conversations?
No. Messages are logged as plain-text Notes on the Contact, not as HighLevel Conversations, so the client inbox stays reserved for live replies.Is the integration one-way or two-way?
One-way. Activity flows from Masterinbox into HighLevel, and nothing is written back to Masterinbox.Can I use HighLevel records as a block list?
Not today. Block lists come from HubSpot lists or Salesforce reports. The HighLevel beta syncs activity in only.Do I need admin access to set it up?
The HighLevel user who authorizes the Location must use the same email as their OutboundSync login.Which Masterinbox plan do I need?
OutboundSync receives Masterinbox activity through webhooks. Confirm your Masterinbox plan includes webhook access, or ask us to check during setup.How is Masterinbox + HighLevel priced?
Beta access is scoped with the OutboundSync team during onboarding. Billing follows the same model as every plan: sent messages per month. Replies, opens, clicks, and lead-category updates are not billed. See the pricing page.Can I do this with Zapier, Make, or n8n?
Yes, for lightweight automation. Zapier, Make, and n8n are good for prototypes and simple routing, but they need ongoing maintenance and bill by task or step. OutboundSync is pre-built for outbound CRM sync, keeps searchable event logs beyond 30 days, and prices by outbound volume.What breaks first when this scales?
Data quality and reliability break first: duplicate events, retries, out-of-order webhooks, and bursts during big sends. OutboundSync handles idempotency, timing buffers, and queue recovery, and flags suspicious or mismapped payloads instead of writing them.
Masterinbox resources
Tutorials, case studies, and updates related to Masterinbox.
See Masterinbox activity in HighLevel
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